Feeding attachment for bitstocks



K. W. KARLSSON.

FEEDING ATTACHMENT FOR BITSTOCKS. APPLICAIION FILED JULY 11.1919.

1,339,958. I Patented May 11, 1920,

KARL W. KARLSSON, OF EAST BOSTON, MASSACHUSETTS.

FEEDING ATTACHMENT FOR BITSTOCKS.

Specification of Letters Patent.

Patented May 11, 1920.

Application filed July 17, 1919. Serial No. 311,443.

To all whom it may concern:

Be it known that I, KARL W. KARLssoN, a citizen of Finland, and resident of East Boston, county of Suffolk, Commonwealth of Massachusetts, have invented an Improvement in Feeding Attachments for Bitstocks, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts in each of the several views.

In the work of carpenters it is often required to drill a hole through or into metal or other relatively hard material and to do this it has been customary to substitute a metal drill for the wood boring bit in the usual wood boring bit stock. Since the metal drill in contrast with the boring bit is not self-feeding, but requires considerable pressure to force it into the work, this method of drilling holes in metal has been laborious and difiicult, requiring of the operator a heavy continuous pressure to feed the drill forward. A principal object of the present invention is to provide an attachment capable of being applied to an ordinary boring bit stock at will, as required, to adapt the same for drilling in metal or other hard substances with an automatic positive feed actuated by the movement of the bit stock itself and adapted to force the drill through the material at a proper predetermined rate. The attachment of the invention is of a character so as to be instantly assembled with, or dis-associated from, the bit stock and is adapted to be included as a part of the carpenters equipment to be used as occasion requires, the bit stock at other times being usable for ordi nary purposes since it requires no modification whatever to adapt it for cooperation with the present attachment. The foregoing and other objects and advantages of the invention will more fully appear from the following detailed description, and the distinctive features of novelty will be pointed out in the appended claims.

Referring to the drawings:

Figure 1 is a side elevation showing the attachment of the invention assembled for use with a bit stock, an intermediate portion of the frame being broken away; and

Fig. 2 is an elevation taken at right angles to Fig. 1 and with parts broken away.

In accordance with my invention a suitable frame 10 is provided having a lower horizontal portionlO serving as a rest for a work piece W and an upper horizontal portion 10 constituting a holder and backing for the attachment proper of the invention. Through a hole 10 in the horizontal portion 10 of the frame is passed a threaded stud 11 which extends from and is rigid with a yoke bar or block 12. The block 12 is adapted to be clamped removably to the frame portion 10 by a wing nut 13 engaged on the threaded stem 11. Threaded vertically through the central portion of the block 12 is a stout feed screw 14, This screw has swiveled to reduced extensions 14, l4; at the top and bottom thereof respectively yoke plates 15, 16. These plates have fixed at the extremities thereof connecting bolts 17 18 which being clamped to said yoke plates constitute therewith a rigid frame. The bolts 17 18 are slidably fitted through holes 19 in the extremities of the block 12. The lower reduced extension 14 of the feed screw 14 is equipped with a center point adapted to engage a presser head H of a bit stock S which is shown as having fitted therein a metal drilling bit B. To the top of the screw extension 14c is secured a disk 20 having a ratchet face 20" on the top surface thereof. The ratchet face 20 is engaged by a spring pressed pawl 21 which is pivoted at 22 to a bell crank lever 23, said pawl being held pressed against said ratchet face by a suitable spring 2 1. The bell crank lever 23 is pivoted to an outwardly extending pivot pin 25 which is rigid with the frame plate 15 and a lower depending arm 23 thereof is equipped with a pin 26 which is engaged by a curving cam surface 27 formed on a vertically slidable cam plate 27. The cam plate 27 is guided to slide in an approximately vertical direction, for this purpose having slots 28, 29 therein, the former of which engages with the pivot pin 25 and the latter with a pin 30 projecting from the lower plate 16. A tension spring 31 anchored to the pin 30 is engaged with the cam plate 27 tending constantly to draw it downward. The upper slot 28 is shown as somewhat inclinedto the vertical so that as the plate 27 is moved upward it is also tilted by the obliquity of said slot which cooperates with and increases the action of the cam edge 27 a on the lever pin 26. The lower end of the cam plate 27 is formed with a curved cam surface 27 which is in position to be engaged by the upper crank arm C of the bit stock S on each rotation thereof. The ratchet disk 20 may be clamped to the screw extension 14* in any suitable manner as by means of a wing nut 32 engaged with a reduced and shouldered extremity of the screwextension. It may now be understood that when it is desired to make use of the device the bit stock is applied thereto as shown and on the turning of the bit stock at each rotation of the same the upper crank arm C engaging the cam edge 27* will lift the plate 27 causing the cam edge 2" thereof to actuate the bell crank lever 23 and through the pawl 21 and ratchet disk 20 to rotate the screw 14L. This causes the screw bearing with it the sliding frame composed of the plates 15, 16 and the bolts 17, 18 to move downward, the screw extension 142 engaging the bit stock head H and feeding the bit through the work piece. As herein shown the bell crank lever 23 bearing the pawl 21 is returned by gravity after an operative movement but it will be understood that if desired a suitable 1 spring may be applied thereto insuring'the return movement thereof even when the device is operated in other than an upright position. I am aware that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and therefore desire the present embodiment to be considered in all respects as illustrative and not restrictive, reference being had to'the appended claims rather than to the foregoing description to indicate the scope of the invention.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An attachment for use with U-orank bit stocks, comprising a relatively fixed member affording a support forthe work, a block fixed theretohaving a feed screw threaded therethrough, and means for operating said feed screw at each rotation of arm of the bit stock at each rotation thereof.

An attachment for use with U-crank bit stocks, comprising a member affording a support for the work, a member detachably iixed thereto having a feed screw in threaded engagement therewith, said screw having an extremity adapted to impinge and press on the head .ofthe bit stock, anda pawl and ratchet device equipped with a member engaged for actuation by an arm of the bit stock at each rotation thereof.

at. An attachment for use with lJ-crank bit stocks, comprising a feed screw, means for supporting the same for feed movement with respect to a work piece, said screw adapted to press on the head of abit stock to advance the same, and means for rotating said screw actuated by engagement with a crank arm ofthe bit stock at each rotation thereof.

5. An attachment for use with U-crank bit stocks, comprising a screw mounted for feed movement with respect to a work piece and adapted to detachably engage the head of a bit stock, a pawl and ratchet device for advancing said screw, and means for operating said pawl and ratchet device consisting in a slidably mounted cam plate arranged to be engaged and moved operatively by a crank arm of the bit stock at each rotation thereof.

In testimony whereof, I have'signed my name to this specification.

KARL W. KARLSSON. 

